Inlet bearing lubrication for a screw machine

Abstract

The inlet bearings of a screw machine, such as a refrigerant compressor, are both lubricated and cooled by a portion of the motor cooling and suction flow which has lubricant entrained therein and which is drawn through the inlet bearings into the coacting pair(s) of screw rotors.

What is claimed is:  
     
       1. A screw machine comprising: 
       means defining a casing having an inlet and an outlet;  
       at least two coating rotors located in said casing;  
       inlet and outlet bearing means for supporting each of said rotors in said casing;  
       motor means located in said casing for driving one of said rotors;  
       means for supplying a motor lubricant containing fluid into said casing for cooling said motor;  
       means for supplying a bearing lubrication containing fluid into said casing via said inlet;  
       said motor means being located in said casing between said means for supplying a motor lubricant containing fluid into said casing for cooling said motor means and said inlet whereby all of said motor lubricant containing fluid supplied to said casing for cooling said motor means must pass through and thereby cool said motor means before combining with said bearing lubricant containing fluid supplied to said casing via said inlet;  
       said inlet bearing means providing fluid paths for said bearing lubricant containing fluid supplied via said inlet and for cooling said motor means whereby as said motor means drives said one rotor, at least a portion of said bearing lubricant containing fluid supplied via said inlet and for cooling said motor means passes via said fluid paths and thereby cools and lubricates said inlet bearing means.  
     
     
       2. The screw machine of  claim 1  wherein said screw machine is a refrigerant compressor and said bearing lubricant containing fluid supplied via said inlet and for cooling said motor means is a refrigerant. 
     
     
       3. The screw machine of  claim 1  wherein each of said inlet bearing means includes a bearing retainer annularly spaced from a corresponding one of said rotors with each of said annular spacings forming portions of said fluid paths downstream of corresponding ones of said inlet bearings.